Ricin, a lectin from the castor bean plant Ricinus communis is considered one of the most potent plant toxins. Ricin poisoning can cause severe tissue damage and inflammation and can result in death.

The United States Patent and Trademark Office (USPTO) today rejected all of the patent claims for a common yellow bean that has been a familiar staple in Latin American diets for more than a century.

The Yam bean originated where the Andes meet the Amazon and is locally grown in South and Central America, South Asia, East Asia and the Pacific. It is produced in three species which are called the Amazonian, Mexican and Andean. Interbreeding of the bean has resulted in fertile and stable hybrids.